Medial femoral plate with cannulated screw for Pauwels type III femoral neck fracture: A meta-analysis

Investigation of Novel Radiological Parameters to Predict Treatment Failure and Ideal Surgical Interventions in Young Femoral Neck Fractures Treated with Triple Cannulated Screw: A Retrospective Analysis

Introduction

Treatment failure remains a challenge in young femoral neck fractures treated with triple cannulated screws (TCS). This study aims to identify novel radiological parameters that can predict treatment failure and propose surgical techniques to enhance the success of TCS or aid in selecting alternative methods.

Patients and methods

We conducted a retrospective analysis of 87 patients who underwent surgery for femoral neck fractures between February 2014 and June 2022, meeting the inclusion criteria. Patients achieving union were categorized as Non-Fail (Group 1), while those experiencing nonunion were categorized as Fail (Group 2). Various demographic and clinical factors were assessed, including age, gender, fracture side, and fracture classification (Garden and Pauwels). Radiological parameters such as fragmentation in the medial cortex, postoperative fracture displacement in the calcar region, collo-diaphyseal angle (CDA) difference (varus/valgus alignment), and several newly defined parameters (modified tip apex distance (m-TAD), tip cortex distance (TCD), upper-lower screw-cortex distance/neck diameter, the calcar screw-cortex distance/neck diameter (Buyukdogan index), and sub-capital area/basocervical area (Dogan index) were evaluated. Patients developing nonunion were studied to establish potential cut-off values based on radiological parameters.

Results

Of the patients, 61 were classified as Non-Fail (Group 1) and 26 as Fail (Group 2). Both groups exhibited similar distributions in terms of gender, fracture side, Pauwels classification, and follow-up times (p > 0.05). However, Group 2 had a higher mean age than Group 1 (p = 0.006). There was a significant difference between the two groups in terms of Garden classification (p = 0.0003). Furthermore, postoperative calcar displacement, varus alignment, m-TAD, TCD, upper-lower screw-cortex distance/neck diameter ratio, Buyukdogan index, and Dogan index showed significant differences between the groups (p < 0.05). Conversely, medial calcar fragmentation did not differ significantly between the groups (p > 0.05).

Conclusions

The Dogan index (≤ 0.5) can serve as an independent preoperative predictor of treatment failure, aiding in the selection of more effective surgical interventions than TCS. Varus alignment (> 10 degrees), the upper-lower screw-cortex distance to the neck diameter (> 0.45) and Buyukdogan index (> 0.2) are influenced by the surgical technique of TCS application and should be considered to decrease the success of TCS.

Biomechanical analysis of a new cannulated screw for unstable femoral neck fractures

Background

The treatment of unstable femoral neck fractures (FNFs) remains a challenge. In this study, a new cannulated screw for unstable FNFs was designed to provide a new approach for the clinical treatment of these injuries, and its biomechanical stability was analyzed using finite element analysis and mechanical tests.

Methods

An unstable FNF model was established. An internal fixation model with parallel inverted triangular cannulated screws (CSs) and a configuration with two superior cannulated screws and one inferior new cannulated screw (NCS) were used. The biomechanical properties of the two fixation methods were compared and analyzed by using finite element analysis and mechanical tests.

Results

The NCS model outperformed the CSs model in terms of strain and stress distribution in computer-simulated reconstruction of the inverted triangular cannulated screw fixation model for unstable FNFs. In the biomechanical test, the NCS group showed significantly smaller average femoral deformation (1.08 ± 0.15 mm vs. 1.50 ± 0.37 mm) and fracture line displacement (1.43 ± 0.30 mm vs. 2.01 ± 0.47 mm). In the NCS group, the mean stiffness was significantly higher than that in the CSs group (729.37 ± 82.20 N/mm vs. 544.83 ± 116.07 N/mm), and the mean compression distance was significantly lower than that in the CSs group (2.87 ± 0.30 mm vs. 4.04 ± 1.09 mm).

Conclusion

The NCS combined with two ordinary cannulated screws in an inverted triangle structure to fix unstable FNFs can provide better biomechanical stability than CSs and exhibit a length- and angle-stable construct to prevent significant femoral neck shortening.

Evaluation of full thread screw and different fixation configurations in Pauwels type III femoral neck fracture

Objectives

The purpose of this study is to evaluate the value of full thread screw and different fixation configurations in Pauwels type III femoral neck fracture.

Methods

A total of 40 artificial femoral model specimens were chosen, and Pauwels type III femoral neck fracture was simulated upon osteotomy at 80°. According to random number table, models were divided into four groups (10 cases in each group): Group A received the paralleled fixation with three partial thread screws (PTSs), group B received the crossed fixation with three PTSs, group C received the paralleled fixation with two full thread screws (FTSs) and one PTS, and group D received the crossed fixation with two FTSs and one PTS. Changes including the model rigidity, axial displacement in fatigue test and limit loads for Pauwels type III femoral neck fracture models were analyzed through MTS 858 Mini Bionix Ⅱ test system.

Results

Among four groups, the model rigidity, axial displacement in fatigue test and limit loads were the highest in group D, and they were the lowest in group A. However, the model rigidity, axial displacement in fatigue test and limit loads between group B and group C showed no statistically significant difference (P＞0.05). Eventually, all the specimens were displaced along the fracture lines while the femoral head was split at varying degrees. After splits, the removal rate of fixation screws in group A (60.0 %) and group C (40.0 %) was significantly higher than that of group B (10.0 %) and group D (0 %) (P＜0.05), but it showed no statistically significant difference between group A and group C, and between group B and group D (P＞0.05).

Conclusions

The crossed fixation configuration with two FTSs and one PTS in group D is proven to be more effective, which can go against the shear stress, tension and introversion in Pauwels type III femoral neck fracture models.

Effect analysis of medial bracing plate combined with cannulated screw in unstable femoral neck fracture assisted by surgical hip dislocation: a retrospective study

BACKGROUND

Unstable femoral neck fractures have a high likelihood of causing severe disruption to the blood supply. This study aimed to assess the therapeutic effect of surgical hip dislocation using a medial support plate combined with cannulated screw fixation for the treatment of unstable femoral neck fractures in young and middle-aged adults.

METHODS

We retrospectively analyzed the medical records of 68 young adults who underwent internal fixation of unstable femoral neck fractures. The observation group included 32 patients who had received medial support plate and cannulated screw fixation by the surgical hip dislocation method and 36 patients who had undergone anti-rotation screw composite compression system fixation comprised the comparison group. The amount of intraoperative bleeding, surgery duration, fracture recovery time and complications were recorded. The degree of femoral neck shortening and Garden index were assessed using the Zlowodzki method. Additionally, hip functionality was evaluated using the Harris score at 3 and 6 months and at the last follow-up.

RESULTS

All 68 patients in both groups were followed up for 12-42 months (mean, 22.4 months). The postoperative incision was well-aligned and no inflation was observed. The intraoperative blood loss and surgery duration in the comparison group were longer than those in the observation. Additionally, the observation group had a significantly shorter fracture recovery time and a higher Garden index than the comparison at 6 months postoperatively; however, there was no significant statistical discrepancy between the two groups at the remaining time points. The observation group had higher Harris scores than the comparison at 3 and 6 months postoperatively.

CONCLUSION

Surgical hip dislocation applied to the medial support plate combined with cannulated screw fixation has clinical application value in restoring the stability of femoral neck fractures while facilitating the maintenance of blood flow to the femoral head and neck.

Research hotspots and trends in internal fixation of femoral neck fractures from 2010 to 2022: A 12-year bibliometric analysis

BACKGROUND

This study endeavors to scrutinize the hotspots and trends in the literature concerning the internal fixation of femoral neck fractures (INFNF) through a comprehensive bibliometric analysis. Notably, this analytical process encompasses both qualitative and quantitative components.

METHODS

The present study has utilized the Science Citation Index-Expanded from the Web of Science Core Collection to extract datasets ranging from January 1, 2010, to August 31, 2022. Quantitative analysis was carried out using sophisticated analytical tools such as the Bibliographic Item Co-Occurrence Matrix Builder, the Online Analysis Platform of Literature Metrology, and CiteSpace software. Further, the major Medical Subject Headings terms and their subheading counterparts associated with INFNF were extracted from the PubMed2XL website using the corresponding PMIDs. These Medical Subject Headings terms were employed in conducting a co-word clustering analysis. Ultimately, the Graphical CLUstering TOolkit program was utilized to execute a co-word biclustering analysis to discern the prevailing hotspots in this domain.

RESULTS

Between January 1, 2010, and August 31, 2022, a total of 463 publications were issued on INFNF. The INJURY-INTERNAL JOURNAL OF THE CARE OF THE INJURED stood out as the most extensively perused journal in this area. Notably, China emerged as the foremost contributor to publishing articles within the last 12 years, followed by the United States and Canada. McMaster University was identified as the leading institution in INFNF research, while Bhandari M emerged as the most prolific author in this field. Moreover, the study identified five notable research hotspots within the domain of INFNF.

CONCLUSIONS

This study has identified five critical areas of research in the field of INFNF. It suggests that the primary focus of future research is likely to center on advancing internal fixation methods and robot-assisted instrumentation for femoral neck fractures. As such, this study provides valuable insights into future research directions and ideas for those working in this field.

Mechanical study of the application of compression screw nails in the cross-inverted triangular pattern for internal fixation of femoral neck fractures

OBJECTIVE

To design a cross-inverted triangular pattern to insert compression screw nails for the treatment of femoral neck fractures and to compare the biomechanics of inserting compression screw nails in cross-inverted triangular patterns and inverted triangular patterns. I am very sorry that a corresponding author needs to be added to the article. I do not know how to insert it, so I make a note here. Please check the attachment I uploaded.

METHODS

The reasonableness of the model is first analyzed using finite elements. A total of 6 adult human specimens were selected, of which 3 males and 3 females were divided into the A1, B1, and C1 groups and the A2, B2, and C2 groups by the random number table method. The A1 and A2 groups were made into subhead femoral neck fracture models, the B1 and B2 groups were made into trans-neck femoral neck fracture models, and the C1 and C2 groups were made into basal femoral neck fracture models. The right femur of each group had a compression screw nail inserted in the crossed-inverted triangular pattern, and the left femur of each group had a compression screw nail inserted in the inverted triangular pattern. The static compression test was performed by an electronic universal testing machine. The maximum load of the femoral neck and the load of 3.00 mm axial displacement of the femoral head were read according to the pressure-displacement curve drawn in the experiment.

RESULTS

The finite element analysis showed that the cross-inverted triangular hollow threaded nail has better conductivity and more stable fixation than the inverted triangular hollow threaded nail. The maximum load of the femoral neck and the load of 3.00 mm axial displacement of the femoral head of the left femur were greater than those of the right femur in the A1, A2, B1, B2 and C2 groups, while the maximum load of the femoral neck and the load of 3.00 mm axial displacement of the femoral head of the left femur were smaller than those of the right femur in the C1 group. There was no statistically significant difference in the maximum load of the femoral neck or the load of 3.00 mm axial displacement of the femoral head between the A1 and A2 groups, the B1 and B2 groups, or the C1 and C2 groups (P > 0.05). After the K-S test, the maximum load of the femoral neck and the load of 3.00 mm axial displacement of the femoral head were normally distributed (P = 0.20), and the LSD-t test was conducted for the two load data; the difference was not statistically significant (P = 0.235).

CONCLUSION

The effect of compression screw nails in the cross-inverted triangular pattern was the same in males and females, and stability was better in the fixation of subhead and trans-neck femoral neck fractures. However, its stability in fixation of basal femoral neck fracture is worse than that of the inverted triangular pattern. The cross-inverted triangular hollow threaded nail has better conductivity and more stable fixation than the inverted triangular hollow threaded nail.

Biomechanical comparison of femoral neck system and cannulated screws coupled with medial plate for treating Pauwels III femoral neck fractures

BACKGROUND

The femoral neck system (FNS) has been considered as a novel strategy for femoral neck fracture. The diversity of internal fixation creates difficulties in choosing an effective option for Pauwels III type femoral neck fractures. Therefore, it is significant to investigate the biomechanical effects of FNS versus conventional approaches on bones.

OBJECTIVE

To evaluate the biomechanical characteristics of FNS versus cannulated screws coupled with medial plate (CSS+MP) for the treatment of Pauwels III type femoral neck fractures.

METHODS

Through three-dimensional computer software (Minics, Geomagic - Warp), the proximal femur model was rebuilt. Based on the present clinical characteristics, models of internal fixation were reconstructed in SolidWorks, including cannulated screws (CSS), medial plate (MP) and FNS. After parameter setting and meshing, boundary conditions and loads were set up for the final mechanical calculation in Ansys Software. Under identical experimental conditions, such as the same Pauwels angle and force loading, the peak values of displacement, shear stress and equivalent (von Mises) stress were recorded.

RESULTS

This study showed that the displacement of the models was CSS, CSS+MP, and FNS in descending order of magnitude. The shear stress and equivalent stress of the models was CSS+MP, FNS, and CSS in descending order. The principal shear stress of CSS+MP was concentrated on the medial plate. The equivalent stress of FNS was more dispersed and distributed from the proximal main nail to the distal locking screw.

CONCLUSION

CSS+MP and FNS exhibited better initial stability compared to CSS. However, the MP was subjected to more shear stress, which could increase the risk of internal fixation failure. Due to its unique design, FNS may be a good choice for the treatment of Pauwels III type femoral neck fractures.

The effects of full weight-bearing mobilization on clinical outcomes and subsidence in cemented and uncemented hemiarthroplasty in osteoporotic patients: A retrospective single-center study

BACKGROUND

Early full weight-bearing mobilization is controversial in osteoporotic patients who have undergone uncemented hemiarthroplasty (UCH).

OBJECTIVES

The aim of the study was to compare the results of early full weight-bearing mobilization in CH and uncemented hemiarthroplasty (UCH). The effect of subsidence on the results was also evaluated.

METHODS

Fifty-nine patients who underwent CH and UCH were evaluated. The mean age was 79.8 years (10 females, 15 males) for CH and 75.5 years (10 females, 24 males) for UCH. All patients started immediate full weight-bearing mobilization and weight-bearing exercises.

RESULTS

There was no difference between the groups according to the Harris Hip Score. Both groups were evaluated in subgroups according to whether there is varus in the femoral stem. There was no difference between subgroups according to the Harris Hip Score. The femoral subsidence was not determined in CH group. In the UCH group, the subsidence was 1.13 ± 1.03 mm in varus femoral stem subgroup and 0.81 ± 0.85 mm in without femoral stem varus subgroup. There was no difference in subsidence between femoral stem with varus and without varus. The subsidence did not affect the Harris Hip Score.

CONCLUSION

Full weight-bearing mobilization could be safely preferred in UCH, as in CH. Femoral stem varus below 5 degrees does not affect the results and subsidence.

Medial Buttress Plate and Allograft Bone-Assisted Cannulated Screw Fixation for Unstable Femoral Neck Fracture with Posteromedial Comminution: A Retrospective Controlled Study

Objective

To investigate the outcomes of open reduction and internal fixation combined with medial buttress plate (MBP) and allograft bone‐assisted cannulated screw (CS) fixation for patients with unstable femoral neck fracture with comminuted posteromedial cortex.

Methods

In a retrospective study of patients operated on for unstable femoral neck fractures with comminuted posteromedial cortex from March 2016 to August 2020, the clinical and radiographic outcomes of 48 patients treated with CS + MBP were compared with the outcomes of 54 patients treated with CS only. All patients in the CS + MBP group were fixed by three CS and MBP (one‐third tubular plates or reconstructive plates) with bone allografts. The surgery‐related outcomes and complications were evaluated, including operative time, blood loss, union time, femoral head necrosis, femoral neck shortening, and other complications after the operation. The Harris score was evaluated at 12 months after the operation.

Results

All patients were followed up for 12–40 months. The average age of patients in the CS‐only group (54 cases, 22 females) and CS + MBP group (48 cases, 20 females) was 48.46 ± 7.26 and 48.73 ± 6.38 years, respectively. More intraoperative blood loss was observed in the CS + MBP group than that of patients in CS‐only group (153.45 ± 64.27 vs 21.86 ± 18.19 ml, t = 4.058, P = 0.015). The average operative time for patients in the CS + MBP group (75.35 ± 27.67 min) was almost double than that of patients in the CS‐only group (36.87 ± 15.39 min) (t = 2.455, P < 0.001). The Garden alignment index of patients treated by CS + MBP from type I to type IV was 79%, 19%, 2%, and 0%, respectively. On the contrary, they were 31%, 43%, 24% and 2% for those in the CS‐only group, respectively. The average healing times for the CS‐only and CS + MBP groups were 4.34 ± 1.46 and 3.65 ± 1.85 months (t = 1.650, P = 0.102), respectively. Femoral neck shortening was better in the CS + MBP group (1.40 ± 1.73 mm, 9/19) than that in the CS‐only group (4.33 ± 3.32 mm, 24/44). Significantly higher hip function was found in the CS + MBP group (85.60 ± 4.36 vs 82.47 ± 6.33, t = 1.899, P = 0.06). There was no statistical difference between femoral head necrosis (4% vs 11%, χ² = 1.695, P = 0.193) and nonunion (6% vs 9%, χ² = 0.318, P = 0.719).

Conclusion

For unstable femoral neck fractures with comminuted posteromedial cortex, additional MBP combined with bone allografts showed better reduction quality and neck length control than CS fixation only, with longer operative time and more blood loss.

Factors Associated with Femoral Neck Shortening After Closed or Open Reduction and Screw Fixation

PURPOSE

This study aimed to evaluate the incidence of femoral neck shortening (FNS) after the treatment of displaced and non-displaced femoral neck fractures with closed or open reduction internal fixation, and determine the independent factors associated with this condition.

METHOD

The study included 81 patients who underwent internal fixation by closed or open reduction with multiple screws between 2013 and 2018 due to femoral neck fracture (FNF) and were followed up for at least 1 year. Patients were divided into two groups as with and without FNS. The patient, fracture, and surgical parameters compared between the two groups, and the factors affecting development of FNS were investigated.

RESULTS

Internal fixation was applied by closed reduction in 56 patients (69.1%) and open in 25 (30.9%). FNS was detected in 41 patients (50.6%), with the mean shortening 6.3 ± 6.4 mm. Fracture union achieved in 72 patients (89%). The mean time to fracture union was 4.3 ± 2.3 months.No statistically significant relationship found between FNS and the parameters of gender, age, smoking, reduction type, number, type and orientation of screws, Singh index, and Garden fix index (p > 0.05).However, there was significant difference between two groups regarding energy of the fracture, fragmentation, coronal angulation, Garden type, and fixation with medial buttress plate (p < 0.05).

CONCLUSION

FNS is an expected condition in FNF fixed by screws. Patients with high-energy traumas and advanced Garden types are more likely to have FNS. The use of medial plate may be effective in preventing FNS.